In recent years, Liquid Crystal Displays (LCDs) have been widely used in electronics for representation of information due to their lightness, thinness, low power consumption, etc.
Conventional LCDs are broadly classified as either reflective or transmissive. Unlike Cathode Ray Tube (CRT) displays and Electroluminescent (EL) displays, LCDs are not self-emissive. A transmissive LCD is illuminated by a light source situated behind the LCD panel, and a reflective LCD is illuminated by ambient light. As a result, transmissive LCDs are less subjected to the intensity of ambient light and the contrast of the displayed image is higher, but transmissive LCDs are less power efficient due to the presence of the light source. Reflective LCDs are more power efficient because they do not need an additional light source, but the brightness and contrast of the displayed image in reflective LCDs are more subjected to the intensity of ambient light and the like. Particularly, their ability to resolve detail is notably limited in a dark environment.
A Field-Sequential Color Liquid Crystal Display (FSC-LCD) is a display with many advantageous features. The display switches on red, green and blue (R, G, B) backlights in sequence, which illuminate the display panel in sequence. That is, red, green and blue lights are applied in each pixel in sequence. Due to image sticking, the red, green and blue images are perceived by the observer as a continuous image.
Now refer to FIG. 1, a sectional view of the structure of a conventional FSC-LCD 1. The FSC-LCD 1 includes a first upper substrate 10, a first lower substrate 11, a first liquid crystal layer 12 provided between the first upper substrate 10 and the first lower substrate 11, and a first backlight device 13 for providing the light source of the FSC-LCD 1. The first backlight device 13 including a plurality of red Light-Emitting Diodes (LEDs) 13r, green LEDs 13g and blue LEDs 13b. First pixel electrodes 111 and Thin-Film Transistors (TFTs) 112 used as switches are formed on the side of the first lower substrate 11 immediately adjacent to the first liquid crystal layer 12. The TFTs 112 are electrically connected to the first pixel electrodes 111. A first common electrode 101 facing the first pixel electrodes 111 is formed on the side of the first upper substrate 10 immediately adjacent to the first liquid crystal layer 12. A black base 102 is provided between the first common electrode 101 and the first upper substrate 10, and in correspondence with the TFTs 112 of the first lower substrate 11, for blocking light from the regions excluding the first pixel electrodes 111 of the first lower substrate 11.
FIG. 2 is a top view of the first lower substrate 11 of the conventional FSC-LCD 1. The TFTs 112 used as pixel switches, data lines 113 for providing signals to the first pixel electrodes 111 of the first lower substrate 11, and gate lines 114 for providing switching signals to the TFTs 112 are provided on the first lower substrate 11. The data lines 113 and the gate lines 114 define multiple pixel regions 115. Each of the TFTs 112 is on the place in a pixel region 115, where a data line 113 and a gate line 114 meet, and is electrically connected to the data line 113 and the gate line 114.
FIG. 3 is a sequence diagram illustrating a method for driving the conventional FSC-LCD 1. The method for driving the FSC-LCD 1 includes: scanning each of the TFTs 112 according to the first backlight device 13, and realigning liquid crystal molecules in the first liquid crystal 12 to correspond to the lights emitted by the red LEDs 13r, green LEDs 13g and blue LEDs 13b of the first backlight device 13. Specifically, scanning of all of the TFTs (tTFT) 15, liquid crystal response (tLC) 16 and backlighting (tBL) 17 in the FSC-LCD 1 are performed in the period of a field 14.
FIG. 4 illustrates the principle of driving the conventional FSC-LCD 1. The FSC-LCD 1 further includes a first scanning driver 18 and a first data driver 19. With reference to FIG. 2, the first lower substrate 11 of the FSC-LCD 1 includes multiple pixel regions 115, and pixels in all the pixel regions 115 form an array. The first scanning driver 18 scans pixels in the pixel regions 115 row by row in sequence, and the first data driver 19 transmits the image data to a pixel column corresponding to the pixel regions 115.
However, for good outdoor readability of the conventional FSC-LCD 1 discussed-above, the brightness of light produced by the first backlight device 13 has to be elevated, resulting in increased power consumption.
In view of the problem in the prior art, the inventors conducted intensive studies with their vast experiences in the field, and invented the outdoor-readable LCD of the invention.